A do-it-yourself approach to bike ridership data

By

Martine Powers

June 28, 2013

Call it D.I.Y. traffic counting.

The process of pinning down exactly how many people ride bikes in Boston is a notoriously imperfect science. Ari Ofsevit, who runs the blog “Amateur Planner’’ — though he says he’s more “armchair’’ than “amateur’’ — was underwhelmed by the state’s data on bike use on Longfellow Bridge. The state’s most recent numbers, from 2011, suggest that a little more than 100 cyclists cross the bridge in a two-hour time frame during a peak period of the day.

Which, if you’ve ever been on the bridge during rush hour, seems like a shockingly low estimate.

Advertisement

So Ofsevit hatched a plan to conduct his own ridership count, Ninja-style.

“Instead of getting mad, I got even,’’ Ofsevit wrote. “I did my own guerrilla traffic count. On Wednesday morning, when it was about 60 degrees and sunny, I went out with a computer, six hours of battery life and an Excel spreadsheet and started entering data.’’

His results?

During the two-hour period he was stationed at the bridge, he saw 463 cyclists — more than four times state estimates.

He also discovered other interesting details, too — only about 6 percent of the cyclists crossing the bridge were on Hubway bikes.